SHED MATTERS 2

[Stanley]

Oh Dear!! I must look that up today, I'll bet the old bugger did some bastarding!! I'm sure he reads this... Hard luck John but you know what went wrong, you took too much off... If you're thinking about sleeving it, sleeve the blank and not the chuck. Best way to do it is turn enough off to make the sleeve 1/2" wide, use EN8 or better if possible but mild steel will do and turn it a thou shy for every inch of diameter. Heat it until it drops on and leave to cool. This was how Newton shrunk cranks onto flywheel shafts. It will never move and you can start again. I'm not laughing and Newton wouldn't either, these things happen and the trick is how you retrieve the mistake and still get the right result. If things get really bad send dimensions and I will measure my blanks up. If they get even worse, bring the chuck over and we'll have a crack at it....
As for welding the bed together, my brain has been working on it and I want to do it myself even though I am a lousy welder and almost blind.... I've watched my mate Dennis welding 'D' patches where a curved piece has to be welded on to a flat piece and kept absolutely vertical. I've got a good welder and the rods.... It will be good for my self-esteem if I can manage it! I have worked out a cunning scheme....
Today will be some very crafty marking out of holes.....

07:20. Today's task. If anyone knows any cause or just impediment why these two should not be joined in matrimony let him speak now or forever hold his peace.

[Whyperion]

Would you be drilling and plugging first to hold the verticals in place?

[Stanley]

What I was after here is a register mark on the lid on the centre line of the cylinder and valve chest that I can use to ensure that when fitted, the valve chest is at 90 degrees to the bed of the engine. They look terrible if it isn't! Too many lumps and bumps in the way so I used this toolmaker's clamp, set so that the jaws are parallel to give me something to refer to against the valve chest lid. When I thought I had it right I marked the lid and then put two punch marks in level with each jaw. Then I measured the distance between the punch marks, split in in two and marked the lid near the edge.



You can see the punch mark here. I've done my best to get it accurate but it's hard when you can't see!



Once I had it marked, off with the lid.



One of the ubiquitous 3/8" cap screws through the lid and clamp it down tight in the right position.





Set up in the vice and drilled 3/16" which is clearance for 2BA.



The plate after drilling. All the holes lightly countersunk.



Three jaw off and four jaw onto the lathe. The compressor came in handy to blow all the muck out of the threads....



Once I'd centred it I poked a 1.25" drill through for the boss of the gland.



I'm bragging here, both flutes of the drill cutting evenly......



I'm just checking the interference of the small chamfer it the base of the boss. I shall have to chamfer the hole to allow the lid to seat properly when I bore the register. I'll have to put the chamfer in before I can properly bore the register. But that's for tomorrow. Quite enough stress for one day... (I wonder whether I got all that right. I shan't know till I can do a trial fit.)

[Stanley]

I've just watched John's video. I was mistaken of course when I said shrink a hoop on because I thought he'd cocked up on the register with the chuck, not the nose.
Of course John is working under difficulties here because by rights the back plate should be made on the nose it is going to fit and it's a lot easier to get the register on the nose right if you are. I feel for him.... If I remember right the last one I made I had the luxury of taking the chuck off with the back plate still in it and trying the fit on the nose by reversing everything because I cut the thread first. I did the same thing with the thread to check the fit.

[Stanley]

I had decided not to mess about with a chamfer to accommodate the fillet at the base of the stuffing box on the lid so I just bored the centre out until the boss dropped in flat. The register is going to be the periphery of the lid so no point complicating matters.



Then I resharpened the boring tool and made sure I could cut a flat bottom and a good periphery. I gave the target end a whack with the hammer to make sure it was flat, checked the jaws for tightness and started cutting the register.



I only took 20 thou cuts because of the vibration in the boring tool when it hit the interrupted cut over the bolt holes. Once I had a definite edge I did some measuring worked out where the limit was, set that as Zero on the dial and just took quiet cuts until I thought I was deep enough.



This is the best way to tell if you have a good register. I had to tap the lid into place and then had a bit of a job getting it off again. No matter, we have a fit.



The next job was to make sure the holes in the target end coincide with those in the lid when it is tight in the register. No problem really, they are all tight but only two needed easing with a rat tail file.



Then the real test... marring the end and the lid up to the cylinder. Again, snug fits but no problem. The 1/4" drive socket ratchet with the 2BA socket came in handy... You can never have too many spanners!



I set all the bits of the bed up and it's all looking good.



This was perhaps the most important check, was the cylinder square with the target end.... Perfect!



Next important check. Get the Brown and Sharpe height gauge out and see how close my centre line is to 2" over the base of the bed. It looks to be 5 thou over but that's nothing and it might be my eyes seeing crooked anyway!



The last job before I knocked off was to mark the position on the bed of the beginning and end of the stroke of the piston. This governs where the cross head slide will have to be. It looks OK. I have room to play with it.

That was a good morning! I hope you all did as well.

[micktoon]

Hi Stanley, I checked earlier on and you had not reported any action so thought you must have been having a day off ....................looks like I was wrong . You have had a very productive day indeed , things are looking very nice indeed too.
I think John will be able to sort the backplate out ok now, I bet he was as sick as I was when I did the same , I then wrecked the treading section too so it was a lost cause , I am sure John will make a top job of it in the end and I will make a nice job of his trolley for his Lister for him.
Looking forward to the next instalment Stanley.

Cheers Mick.

[Stanley]

Thanks Mick, John will get there and it will run true, he's a good man. I felt very lucky yesterday but that's how it goes before you make a major cock-up so even more care needed now! What grabbed me was how it all came together out of my head, The brain is a very impressive bit of kit and the best tool in the box! I went to sleep last night with crosshead slides in my mind.....

[Stanley]

We're back from our walk and plotting.... I told you I had crossheads in mind... Before I make the crosshead, which will then govern the height and location of the slide I have some decisions to make about design... If you're looking at the image above and thinking "Hello, he's going to cheat again!" You are dead right. What you are looking at above is the start of a traction engine Newton started making when he was young. He made the cylinder block (note how it has a curved base to fir on top of the boiler), the con rod, the crankshaft and the horn plates. Then Johnny rained on his parade by telling him there were far too many studs and all in the wrong place! (I'm forced to admit that Johnny had a point). Newton saw that his dad was right, chucked everything into the back of a drawer and started on another project. Years later when he was clearing out he chucked it into the scrap as he was moving into a much smaller shed after Olive died. This was when I collared a lot of stuff that later turned out to be related to the 1937 and 1956 lathes. So I grabbed it and it's been sat in the treasure chest ever since.
I got it out this morning and did a few measurements. Would you believe it's 2" stroke, the same as my new cylinder? So the crankshaft will fit with a few modifications. Before you start tut-tutting, I'm 79 on the 14th and time is limited! Do I want to spend all that time chopping a new shaft out of the solid? The answer is definitely not and it will be nice to have a bit of my old mate in the engine. I haven’t reckoned the con rod up yet but if it's right it will determine the design of the crosshead block....
Pity about the cylinder, it's beautiful work but a cock up. Notice that Newton had converted to screw in gland nuts even in his early years....
I've just been in the shed and offered the con rod up... It will be perfect. I might need to extend the bed plate slightly to give the shaft a good base but that's easy. Far easier than making a new shaft and con rod! So I know now how I have to make the crosshead block. That is today's task. Once I've made that I can get the dimensions of the slide. Onward and up[ward.....

[Stanley]

Take the 4 jaw off, put the 3 jaw SC on, pop the dead centre in and face it true.... Not strictly necessary but we might as well have it right!



Put some tallow and graphite into the centres and mount the flyshaft for a bit of polishing.



A short time later.... Not as crisp as when they were made but seeing as they have been sitting in unheated sheds for at least 70 years, not too bad. Main reason for the clean up is so that they are nicer to handle and measure....



Next job was a materials hunt. I dug into the treasure chest for likely looking lumps of bar and flat plate.



Then into the drawing office and some measuring. One thing has changed since I did the drawing, I'm not going to use a taper pin on the piston rod, I shall thread the end and screw it into the crosshead.



You may well wonder what's going on here.... I first had a good clean up and then when I took the rotary table off the VM I realised there was something I had been wanting to do for a while. The grey box on this shelf is the heavy duty Avometer, the blue one is the inverter for the pillar drill and the Harrison. Both things that never need moving and aren't heavy anyway. The way things were, the heavy 'V' block and the two rotary tables were on the far side of the inverter and meter. So I shifted them down the shelf so that the heavy stuff is at this end and a lot easier to access. While I was at it I took the plug off the inverter, threaded the cable behind the shelf and re-connected it. The wire has been draped over the front of the shelf for 12 Years! Not essential but a big improvement..... Tomorrow I can concentrate on the cross head....

[Stanley]

Shopping day today... And I might write an article... Never mind, more time to consider the crosshead and slide....

Later.... fat chance! The shed won!



I was full of good intentions.... get the shopping and the site done and write a couple of articles... Remember I told you my head would be working on the crosshead? It did and spat out a result as I was walking this morning. Cast your mind back to the remedial work I had to do with the big compound because I was short of room in the low pressure cylinder. If I have a fault it's making my clearances at each end of the stroke a bit tight and I could see that perhaps I was running into the same problem with this one. Rather than have to start putting this right later on by reducing the length of the piston and seeing as how the design of the crosshead hinges largely on the exact position of the end of each stroke, I decided to address the matter. There was a simple solution, turn the registers off the lids to give me more stroke.



This didn't take long to do once I had the lids off and for good measure I reduced the depth of the front gland nut a touch as well.



I popped everything back together (I had to clamp the front lid because of the length of the studs) Pulled the rod right out and measured that length and then pushed it back in all the way, took that measurement and then took that off the first. I had gained a quarter of an inch, the available stroke is now 2.25" and I could still steal an eighth off the piston if necessary. By the way, the piston with its graphited asbestos rings is a lovely fit....



The next job was to get the machine vice back on the VM ready for making the crosshead. One of the holding down bolts had always been tight so I ran a 1/2" Whitworth die nut down it. Little jobs that save time in the long run.



I squared the vice up using John's ball bearing on a stick.... Soon had that sorted. Then I vacuumed all the cast iron dust off the lathe.



It was getting near closing time, everything is ready for the crosshead but I didn't want to start that until I could do it properly. One thing that has been nattering me is that the gussets for the bed aren't quite mirror image and lack finish so I clamped them together and spent 15 minutes on the grinder getting them to match.



Close of play. Looking a lot better. They will have a couple of coats of paint so this finish is perfectly acceptable. Not a bad morning.... Ready for the crosshead now and in good order!

[Stanley]

I gave a bit of thought to the crosshead overnight and looking at the available material I had, I decided that I would be better off making the crosshead slide first and then sizing the crosshead to fit. So, after deciding I wanted 5" I cut a lump off with the HM.



First thing was to clean the stock up and get some square faces on it so I knew what size I had. Its just under 1 1/2" square which is a bit tight but I can make it to. Anything lost in the slide can be made up in the crosshead. Hence this being the best way round.



I squared the ends as well.



Time for some measuring up and decisions. By the way I wasn't looking for a finish with the fly cutter, just a clean surface.



I had a dig in the cutter drawer and found a 1/2" cutter I'd recently sharpened so I put that in the HM and started cutting. It made a good job. The Mick Memorial vice was handy as it's big enough to take the work-piece end on so I didn't need to do any squaring up. I gradually increased the cutter speed and depth of cut, it's a long time since I did any milling in the HM!



The end result. If your eyes are sharp you'll see that I have taken the slot deeper than I recko0ned on. This is because it wasn't until I was cutting that I went to see what I had in the way of a cutter for undercutting the side of the slot for the shoe on the bottom of the crosshead. I thought I had one that was 1/4" cut but found it was slightly deeper. So I've given myself plenty of depth. It doesn't matter if the slide has a deeper groove down the middle under4 the shoe because that will reduce the frictional area.



Ready with the small cutter. It's brand new, I've never used it so no excuses when I come to use it. Once I have the tee slot cut I can re-size my crosshead design....

[PanBiker]

I think I can follow what's going on here Stanley, not being an engineering type I only pick up on a fraction of what you do on the lathe. A bit like you with my creations. Good going anyway for a one eyed bloke!

[Stanley]

You do better than I do with your sparks! This enthusiasm is all well and good, I broke a rule this morning and gid an hour over time. I had my afternoon sleep and got the urge....



I went out in the shed and started under cutting the slot. I speeded the quill up to 530rpm and I'm sure I could have gone higher but this was a full cut in one pass and only a small cutter so plenty of oil and patience.



The second cut was only on one side so it was a bit easier but I took my time. No way I was going to break the only suitable cutter in the drawer! Here's the result. I'm pleased. I have my cross head slide. Making the crosshead itself becomes easier now, all I have to do is machine the shoe to fit the slots leaving plenty of meat up on the top and I can then get exact measurements and finish it off. I shall sleep like a baby tonight.

[Stanley]

When I surveyed the bench this morning it struck me that the end of the crosshead slide fouled two of the cylinder cover nuts. The solution came to me later in the morning. The two bottom studs are in compression when you consider how the weight of the cylinder is hanging and so they aren't actually contributing to the fix of the cylinder on the target end. So I can replace the long studs with short ones and machine a counterbore on the other side of the plate for each bolt head so they don't interfere with the fit of the lid in the plate.



I was tempted into 'improving' the finish on the slide but in truth didn't do much good, the cutter wasn't working properly, I have a lot to learn about milling cutters! Still I did make it a bit better and made sure all the edges were broken before I started measuring.



I popped the saw back on the HM and knocked a 1 1/2" slug off the same stock I used for the slide.



I put a different cutter on, a bit sharper! Then the usual squaring of faces.



And squaring the ends....



While I was squaring the block I realised that I had missed the fact there was a hole in it! No matter, it won't affect anything.



A couple of coats of blue and I was ready for some measuring.



After a while I got my head round the shape and started cutting.



Knocking off time and I have the first element of the shape done. I know it looks big but there is a lot of meat to some off it one way or another. It will shrink and get more beautiful!

[micktoon]

Hi Stanley , more quality work been going on in your shed I am pleased to see, it looks like between the two mills you have everything under control The tee slot cutter did a nice job too. I have seen John today but forgot to pick up the 3/8 Whit die again, I will be seeing him one night this week so will get it then , I would forget my head if it was not attached to my neck

Cheers Mick

[Stanley]

No rush for the die Mick.... I'm beginning to think I run my cutters too slowly.... The 'T' Slot cutter was brilliant and after measuring up, a very accurate cut.....

[Stanley]

We started well, a nice clean shed and a clear task. I found a handy looking cutter, speeded the VM up to 1400rpm and got going.



I didn't get on well at all... I tried everything, slowed the cutting speed and re-sharpened the cutter but got nowhere!



Fresh start needed so a different cutter, an even slower speed and success. My cuts got heavier and heavier....



Full depth in one pass.....



We have the start of a crosshead. A lot more meat to come off yet but we have a block that is a free sliding fit in the slide.



Always a good idea to do some offering up and checking. There's plenty of meat at the correct height to accept the piston rod. In fact that's the next job, to drill and tap the block to accept the rod, fit it and then do some final measuring and removal of surplus metal. This means I have to modify the target end to take the new configuration of the lid bolts. Fasten the slide down on the bed in the right position and then mark the right centre for the piston rod on the crosshead. All this is to make sure that the crosshead and slide are properly lined up in the bed. Quite enough for one day!
For some reason the site isn't talking to me!

[Stanley]

It eventually posted but only after two or three tries!

[Stanley]

The thing that struck me yesterday is that one of the greatest pleasures in making an engine like this, designing it in your head as you go along, is the sitting quietly planning the next move. I have today's task firmly mapped out. By the way, I've decided it's a donkey engine... Scaled up at one inch to the foot it would be quite a powerful one, 2 ft 3" bore and 2" stroke, it would easily give about 100hp with 140psi steam.

[Bodger]

I've decided it's a donkey engine... Scaled up at one inch to the foot it would be quite a powerful one, 2 ft 3" bore and 2" stroke, it would easily give about 100hp with 140psi steam.
Your donkeys a bloody lot bigger than mine

[Stanley]

Didn't know you had one Bodge!





What I am after this morning is getting as near a perfect match between the target end, the bed and the crosshead slide. So I started by taking a light cut over the ends of the slide to make sure they were flat and square.



Once the ends were square I polished the top, two reasons, one to make it look good but more important to give me a good surface for when I need to put some positioning registers on it.





Then the same treatment for the target end and the bed plate.



That's better!



Then I replaced the long bolts in the two holes that interfered with the slide. At the same time I ran the bottoming tap into the other ho;es because having just two bolts tight at one side slightly alters the snug alignment of the other bots. Far better than wasting time later.



The tap wrench set that I thought was a luxury at the time I bought it at Williamson's came in handy again. You can't have too many tools!



A trial fit of the long bolts.



I want to make sure I get the two holding down bolts for the slide in the right place so I clamped it in place and poked a drill right through the slide and the bed. The dowel is to pop in the hole to make sure nothing moves while I drill the next one.



The two dowels in place and a trial set up. It all looks OK.





I'm sure there is an easier way of doing it but this is what I came up with. I've missed a pic here where I had the target end clamped in place with the big Carver clamp. Notice the piston ring on the drill bit, a useful way of making sure you are drilling level.



I drilled tapping size for the cap screw and here it is in place. I knew the hole was on the joint but that's OK, it's for location and will be fine when the bed is bolted down.
Tomorrow I can bolt the bed down, bolt the target end on, fit the cylinder and get an exact register on the crosshead for the piston rod. That's what today was all about!

[Stanley]

I had the slide located by pegs and started this morning drilling and tapping the holes to take 1/4" socket headed cap screws. I tapped the holes before altering the position I had drilled in...



Once I'd started the tap I finished off in the vice and then reversed the slide and put the tap through from the other side to make sure I had a nice thread all the way through. I had counter-bored the holes in the base.





The 3/8" counterbore wasn't quite big enough so I reduced the diameter a touch. I did the target end and then discovered I'd counter-bored the wrong side! This led to a bit of a rethink....



You're allowed to start laughing here.... A blind bloke who is a bad welder anyway welding in the backyard....



I'd ground a deep groove on the line of the weld so there is more metal in the weld than it looks like. By the time I had ground it off it wasn't too bad. Certainly firmly glued to together!



Here's close of play. The weld has pulled the target end back slightly but when I weld the gussets in it will pull it back. It's only a fraction and actually I could live with it as it is now by putting a shim under the front of the slide but I don't think it will be necessary. I'm ready now to prepare the crosshead, a bit more metal off it! And then mount the cylinder and get an accurate mark on it for drilling and threading to take the piston rod.
A high stress morning! But not a bad result...... I can work with this.

[Stanley]

I did so much better than expected with my blind man welding yesterday I have decided to weld the gussets in this morning.... I have found a new use for the stove, baking welding rods. Luckily, when I bought my big oil cooled welder I was flush and went high end. Set correctly it gives a lovely stable arc. By the way, I have it on the same circuit as the electric cooker, 60amp fuse and heavy cable right back to the meter. Nothing worse than a 13 amp supply that keeps tripping out!

[Stanley]

This was the only bit of machining this morning, cutting a packing piece for my welding set up.



I'd decided to get the welding over with and as it was a bit showery did it inside. Everything moved away from spatter and grinding dust... I spent about half an hour working out the best way to clamp the gussets in place. I'm ready to start!
I draw a veil over what followed. It was not pretty, welding is dodgy when you can't see....



This was where I finished up about an hour later. Not good welding but definitely effective in that the gussets were welded in place, solid and square. I ground all the mistakes off..... Some gaps but on the whole things could have been worse. I'd protected my polished slide with masking tape.



I spent half an hour with a file making sure all the sharp edges and odd bits of stray metal and spatter were got rid of and then a good coat of Hammerite black. Covers a multitude of sins....



The finished bed.... The good news is that I was right about the gussets pulling the target end back to vertical if I started the welds in the right place. The target end is perfectly vertical and lined up well with the slide and after all, this was the object of the exercise. On the whole, despite my lousy welding, this is a good result!



I knocked off early, I deserve it! But I had a good clean up all round and got the bench back in order. The grinding dust will keep cropping up for a while but will recede into memory.... I'm ready now to go forward with proper engine building....

[Stanley]

I put the bed on the kitchen table and sat and looked at it for a while.... Next moves are clear, we are nearer an engine than you think!